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-   -   Dominate a room with yeast? (http://www.homebrewtalk.com/f163/dominate-room-yeast-413171/)

sentfromspain 05-27-2013 02:07 PM

Dominate a room with yeast?
 
Hi all, I've recently become acquainted with a new microbrewery which is having a huge problem. You see, these guys have never brewed a beer in their life. They have just started up, and have 1600 liters of beer - 800 in bottles and 800 in the fermenters.

What's the issue? It's all infected with lactobacillus.

Since I come around from time to time and give them samples of my hombrew, they want me to come in and fix this. Now, apart from making double sure that all bottles have been cleaned - which apparently, they tell me they didn't bother to do - and that all the equipment, floors, walls, is treated with industrial strength brewery cleaning chemicals, I also wanted to take an additional step.

I know that there are breweries out there that have open fermentation tanks, and while lots of these guys do this to take advantage of wild yeasts, others do it because the rooms have been dominated by a specific kind of yeast.

My big question:

If - after thoroughly cleaning the brewery - I were to brew a fresh batch of wort and throw in some yeast, let it thrive for a couple of days, and then go around the brewery spraying the walls and floors with that yeast colony, would that yeast dominate the room? Would it be more difficult for a wild yeast like lactobacillus to come in and attack the beer?

Obviously I would have to make sure the brewery was clean again before brewing, but the microorganisms would still be there to a degree I figure. Thoughts?

Shred 05-27-2013 02:12 PM

It seems to me this would invite bacteria once the yeast becomes dormant, no?

highgravitybacon 05-27-2013 02:16 PM

Quote:

Originally Posted by sentfromspain (Post 5226596)
Hi all, I've recently become acquainted with a new microbrewery which is having a huge problem. You see, these guys have never brewed a beer in their life. They have just started up, and have 1600 liters of beer - 800 in bottles and 800 in the fermenters.

What's the issue? It's all infected with lactobacillus.

Since I come around from time to time and give them samples of my hombrew, they want me to come in and fix this. Now, apart from making double sure that all bottles have been cleaned - which apparently, they tell me they didn't bother to do - and that all the equipment, floors, walls, is treated with industrial strength brewery cleaning chemicals, I also wanted to take an additional step.

I know that there are breweries out there that have open fermentation tanks, and while lots of these guys do this to take advantage of wild yeasts, others do it because the rooms have been dominated by a specific kind of yeast.

My big question:

If - after thoroughly cleaning the brewery - I were to brew a fresh batch of wort and throw in some yeast, let it thrive for a couple of days, and then go around the brewery spraying the walls and floors with that yeast colony, would that yeast dominate the room? Would it be more difficult for a wild yeast like lactobacillus to come in and attack the beer?

Obviously I would have to make sure the brewery was clean again before brewing, but the microorganisms would still be there to a degree I figure. Thoughts?

No, this is a horrible idea. You might as well spray feces on the walls. A proper cleaning of everything that can be cleaned is in order.

kombat 05-27-2013 02:24 PM

I would not bother wasting any energy on this endeavour, as it's clear to me that this brewery will not exist for very long.

sentfromspain 05-27-2013 02:29 PM

Well it was a hypothetical thought, but it appears the reaction is super negative.

Then general consensus is clean the crap out of the place x 1000. I still have yet to figure out if they painted the walls with anti-fungal paint. But it seemed to me that the company which had originally evaluated the brewery's capability did a lousy job at talking to them about maintenance.

smokinghole 05-27-2013 02:40 PM

It's not a dominant microorganism issue it's a cleanliness issue. Don't spray the walls with yeast.


How to they clean their fermentors? Are they using caustic cleaner (NaOH with things like chelating agents and antifoam) followed by a nitric acid cycle between each new fermentation? The acid cycle isn't entirely needed each time but if it was me I'd run caustic and acid each time.

Are the fermentors closed cylindroconical fermentors or are they using open top fermentors?

How are they starting each new fermentation? Have they bought a new yeast culture recently or are the contaminated beers all fermented with the same culture? Do they transfer yeast from fermentor to fermentor or do they use a vessel to transfer the yeast? How are they handling a beer at peak of fermentation? Do they use an airlock bucket to catch the foam, or are they pressure fermented?

Do they filter? How do they filter if they do filter? How do they clean the filter if they filter? How do they clean/sanitize their hoses for packaging? How and how often do they clean the bottling line and the kegging line? How are their kegs cleaned? How are their bottles stored?

As you can see there are many sources and points that the contamination can be introduced. The focus needs to be on beer contact surfaces first then after those are all cleaned/sanitized properly they can look at cleaning the whole place up. The reality is that you will never get rid of contaminate microorganisms like bacteria and wild yeast in the brewery, it's just an issue of management and proper cleaning and care of beer contact surfaces.

Are

sentfromspain 05-27-2013 03:45 PM

Thanks smoking. Those are all important things to consider and I will go over it with these guys. The first thing I figure is just throw out the contaminated beer, remove everything that is unnecessary from the brewery, and clean it all with industrial strength phosphoric acid and sodium hydroxide.

As far as I know, they use chemipro oxi - which, when I used it, often didn't do the job for me. It might be a fine cleaner, but what they have here is an agressive bacteria and I would rather use what my friends at other microbreweries use. The fermenters are stainless steel hermetically closed cone fermenters, and have tiny airlocks at the top. I imagine there's nothing wrong with these apart from the fact that they are all full of lacto, so that's a cleaning issue.

No filtering to speak of, and the yeast is dry yeast from a fermentis box. The bottles and caps come straight from the factory, but the brewery owners don't clean before hand - which I think is a major error and so we'll have to put together something to clean the bottles with sodium hydroxide before bottling. The hoses for transferring the wort and beer also seem like a likely place for contamination, so they will have to show me what they do for that.

smokinghole 05-27-2013 04:58 PM

Most breweries in the US are using a peroxyacetic acid sanitizer, some are using an iodine/nitric acid sanitizer like Divosan. A proper cleaning of the fermentors and sanitizing should take care of the contamination. A small contamination testing kit would help out a lot after cleaning them just to make sure. I'd test the final rinse water rather than the vessels themselves. You could also check the bottles but likely they are not the source of the contamination. Most breweries only rinse the bottles prior to packaging rather than a sanitizing step. They should be arriving clean and wrapped to protect them.

The air locks could be the issue because if there is no pressure on the fermentor they could possibly suck in air/dirty airlock water. Are they glycol jacketed fermentors? The only reason I ask is unless the fermentor is actually sealed, when they cool the beer it could cause a slight vacuum allowing the contamination into the batch. Is the manway access a door in the side or is it a bottom manway fermentor. I assume a door in the side because bottom manways are normally on 100bbl and larger fermentors.

How are they filling the bottles/kegs? Those need special attention because if they are automatic fillers there are a lot of valve seats and other gaskets that have had contaminated product pass through.

I would guess it's either their hoses/pumps or possibly the air locks. They either need to run a circulation loop on the hoses and pump with sanitizer or hot water at about 85C.

sentfromspain 05-27-2013 08:05 PM

@smoking, I will figure these things out on wednesday.

Real quick question: what of the following is the best product for cleaning? Alkaline detergent (sodium hydroxide), phosphoric acid detergent, or hydrogen peroxide - peracetic acid detergent? Or is a combination better?

I always use the alkaline and phosphoric, but I do wonder if the peracetic acid is better...

lunshbox 05-28-2013 12:10 AM

Regardless of how far these guys are in over their head, Smokinghole is only about a million percent correct. Also, any plastic or rubber pieces in their system should be replaced. I have specifically set up my brewery to keep all bugs confined to the barrel room. You can not be too careful when it comes to cleanliness. I hear it is next to godliness or something.


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